A Dynamic Composition and Stubless Invocation Approach for Information-Providing Services

The automated specification and execution of composite services are important capabilities of service-oriented systems. In practice, service invocation is performed by client components (stubs) that are generated from service descriptions at design time. Several researchers have proposed mechanisms for late binding. They all require an object representation (e.g., Java classes) of the XML data types specified in service descriptions to be generated and meaningfully integrated in the client code at design time. However, the potential of dynamic composition can only be fully exploited if supported in the invocation phase by the capability of dynamically binding to services with previously unknown interfaces. In this work, we address this limitation by proposing a way of specifying and executing composite services, without resorting to previously compiled classes that represent XML data types. Semantic and structural properties encoded in service descriptions are exploited to implement a mechanism, based on the Graphplan algorithm, for the run-time specification of composite service plans. Composite services are then executed through the stubless invocation of constituent services. Stubless invocation is achieved by exploiting structural properties of service descriptions for the run-time generation of messages

Uma abordagem para interoperabilidade entre plataformas heterogêneas de serviços web para redes colaborativas de organizações

Dissertação (mestrado) - Universidade Federal de Santa Catarina, Centro Tecnológico. Programa de Pós-Graduação em Engenharia Elétrica.Cada vez mais as organizações têm enfrentado um ambiente de intensa concorrência e mudanças de mercado. Para se manterem competitivas e melhorar a colaboração entre parceiros e clientes, as organizações vêm participando de redes colaborativas mais complexas e menos rígidas, como, por exemplo, cadeias de suprimento e organizações virtuais. A Tecnologia da Informação e Comunicação (TIC) vem sendo cada vez mais utilizada como forma de suportar essa colaboração. Porém, isso cria um cenário extremamente heterogêneo, onde organizações diferentes e distribuídas utilizam diversos sistemas de TIC, providos por fabricantes variados e desenvolvidos em diversas plataformas e tecnologias. Portanto, é preciso que sejam oferecidos meios de alcançar uma maior interoperabilidade e colaboração entre as organizações, de maneira padronizada, aberta e dinâmica. Para tal, faz-se necessário utilizar uma abordagem que siga um modelo descentralizado e de baixo acoplamento, permitindo que as organizações possam participar de maneira transparente e interoperável nos processos colaborativos. O paradigma de orientação a serviços, que pode ser implementado através da tecnologia e padrões dos serviços Web, vem sendo largamente utilizado para atingir tal interoperabilidade entre organizações e seus sistemas de TIC. Apesar dos serviços Web serem amparados por padrões, quando as organizações desejam fazer seus serviços, que normalmente são desenvolvidos em diferentes plataformas, linguagens e sistemas operacionais, se comunicarem plenamente entre si, diversos problemas de interoperabilidade surgem na prática. Esse trabalho apresenta uma pesquisa acerca da forma como se aumentar a interoperabilidade e a colaboração entre organizações através de serviços Web, propondo uma abordagem para ocultar a complexidade tecnológica e atingir uma maior interoperabilidade, independentemente da plataforma computacional, das tecnologias e linguagens de implementação, e da localização geográfica do serviço

Services State of Play - Compliance Testing and Interoperability Checking

The document contains an inventory of existing solutions for compliance testing and interoperability checking of services, the assumption being that the services are web services. Even if the emphasis is on geographical information and therefore on Geographical Information Systems, the document describes applicable solutions outside the geographical Information System domain.JRC.H.6-Spatial data infrastructure

Integration of SAP Campus Management into a University SOA

This case study depicts the integration of a legacy university resource planning system (URP) into a Service-oriented Architecture (SOA). The idea is to add the functionality of generating so-called Bologna-conforming Transcript of Records to SAP Campus Management (SAP CM). This is done by adding Web service interfaces to SAP CM that are orchestrated in the SOA using the Business Process Execution Language (BPEL). User Interaction is handled via a central University Portal

Semantic search and composition in unstructured peer-to-peer networks

This dissertation focuses on several research questions in the area of semantic search and composition in unstructured peer-to-peer (P2P) networks. Going beyond the state of the art, the proposed semantic-based search strategy S2P2P offers a novel path-suggestion based query routing mechanism, providing a reasonable tradeoff between search performance and network traffic overhead. In addition, the first semantic-based data replication scheme DSDR is proposed. It enables peers to use semantic information to select replica numbers and target peers to address predicted future demands. With DSDR, k-random search can achieve better precision and recall than it can with a near-optimal non-semantic replication strategy. Further, this thesis introduces a functional automatic semantic service composition method, SPSC. Distinctively, it enables peers to jointly compose complex workflows with high cumulative recall but low network traffic overhead, using heuristic-based bidirectional haining and service memorization mechanisms. Its query branching method helps to handle dead-ends in a pruned search space. SPSC is proved to be sound and a lower bound of is completeness is given. Finally, this thesis presents iRep3D for semantic-index based 3D scene selection in P2P search. Its efficient retrieval scales to answer hybrid queries involving conceptual, functional and geometric aspects. iRep3D outperforms previous representative efforts in terms of search precision and efficiency.Diese Dissertation bearbeitet Forschungsfragen zur semantischen Suche und Komposition in unstrukturierten Peer-to-Peer Netzen(P2P). Die semantische Suchstrategie S2P2P verwendet eine neuartige Methode zur Anfrageweiterleitung basierend auf Pfadvorschlägen, welche den Stand der Wissenschaft übertrifft. Sie bietet angemessene Balance zwischen Suchleistung und Kommunikationsbelastung im Netzwerk. Außerdem wird das erste semantische System zur Datenreplikation genannt DSDR vorgestellt, welche semantische Informationen berücksichtigt vorhergesagten zukünftigen Bedarf optimal im P2P zu decken. Hierdurch erzielt k-random-Suche bessere Präzision und Ausbeute als mit nahezu optimaler nicht-semantischer Replikation. SPSC, ein automatisches Verfahren zur funktional korrekten Komposition semantischer Dienste, ermöglicht es Peers, gemeinsam komplexe Ablaufpläne zu komponieren. Mechanismen zur heuristischen bidirektionalen Verkettung und Rückstellung von Diensten ermöglichen hohe Ausbeute bei geringer Belastung des Netzes. Eine Methode zur Anfrageverzweigung vermeidet das Feststecken in Sackgassen im beschnittenen Suchraum. Beweise zur Korrektheit und unteren Schranke der Vollständigkeit von SPSC sind gegeben. iRep3D ist ein neuer semantischer Selektionsmechanismus für 3D-Modelle in P2P. iRep3D beantwortet effizient hybride Anfragen unter Berücksichtigung konzeptioneller, funktionaler und geometrischer Aspekte. Der Ansatz übertrifft vorherige Arbeiten bezüglich Präzision und Effizienz

Semantic search and composition in unstructured peer-to-peer networks

This dissertation focuses on several research questions in the area of semantic search and composition in unstructured peer-to-peer (P2P) networks. Going beyond the state of the art, the proposed semantic-based search strategy S2P2P offers a novel path-suggestion based query routing mechanism, providing a reasonable tradeoff between search performance and network traffic overhead. In addition, the first semantic-based data replication scheme DSDR is proposed. It enables peers to use semantic information to select replica numbers and target peers to address predicted future demands. With DSDR, k-random search can achieve better precision and recall than it can with a near-optimal non-semantic replication strategy. Further, this thesis introduces a functional automatic semantic service composition method, SPSC. Distinctively, it enables peers to jointly compose complex workflows with high cumulative recall but low network traffic overhead, using heuristic-based bidirectional haining and service memorization mechanisms. Its query branching method helps to handle dead-ends in a pruned search space. SPSC is proved to be sound and a lower bound of is completeness is given. Finally, this thesis presents iRep3D for semantic-index based 3D scene selection in P2P search. Its efficient retrieval scales to answer hybrid queries involving conceptual, functional and geometric aspects. iRep3D outperforms previous representative efforts in terms of search precision and efficiency.Diese Dissertation bearbeitet Forschungsfragen zur semantischen Suche und Komposition in unstrukturierten Peer-to-Peer Netzen(P2P). Die semantische Suchstrategie S2P2P verwendet eine neuartige Methode zur Anfrageweiterleitung basierend auf Pfadvorschlägen, welche den Stand der Wissenschaft übertrifft. Sie bietet angemessene Balance zwischen Suchleistung und Kommunikationsbelastung im Netzwerk. Außerdem wird das erste semantische System zur Datenreplikation genannt DSDR vorgestellt, welche semantische Informationen berücksichtigt vorhergesagten zukünftigen Bedarf optimal im P2P zu decken. Hierdurch erzielt k-random-Suche bessere Präzision und Ausbeute als mit nahezu optimaler nicht-semantischer Replikation. SPSC, ein automatisches Verfahren zur funktional korrekten Komposition semantischer Dienste, ermöglicht es Peers, gemeinsam komplexe Ablaufpläne zu komponieren. Mechanismen zur heuristischen bidirektionalen Verkettung und Rückstellung von Diensten ermöglichen hohe Ausbeute bei geringer Belastung des Netzes. Eine Methode zur Anfrageverzweigung vermeidet das Feststecken in Sackgassen im beschnittenen Suchraum. Beweise zur Korrektheit und unteren Schranke der Vollständigkeit von SPSC sind gegeben. iRep3D ist ein neuer semantischer Selektionsmechanismus für 3D-Modelle in P2P. iRep3D beantwortet effizient hybride Anfragen unter Berücksichtigung konzeptioneller, funktionaler und geometrischer Aspekte. Der Ansatz übertrifft vorherige Arbeiten bezüglich Präzision und Effizienz

Preparing for Service-Oriented Computing: a Composite Design Pattern for stubless Web service invocation

The ability to dynamically bind to Web services at runtime is becoming increasingly important as the era of Service-Oriented Computing (SOC) emerges. With SOC selection and invocation of Web service partners will occur in software at run-time, rather than by software developers at design and compile time. Unfortunately, the marketplace has yet to yield a predominate applications programming interface for the invocation of Web services. This results in software that is deeply ingrained with vendor-specific calls. This is problematic because Web service technology is changing at a rapid pace. In order to leverage the latest developments, code often needs to be heavily refactored to account for changing invocation interfaces. This paper explores the mitigation of this problem through the application of software design patterns